The present invention relates most generally to environmentally safe propulsion systems. More particularly, the invention provides a regenerative pneumatic propulsion system usable in a variety of vehicles and devices.
The need for advanced propulsion systems that are efficient, clean, and environmentally safe is well understood. At present, methods and means enabling pollution-free propulsion are somewhat limited. For example, fuel cell powered vehicles are one example. A well known type of fuel cell utilizes hydrogen and oxygen as a fuel, and produces only water as an xe2x80x98exhaustxe2x80x99 by-product. Given the power densities, especially as a function of weight, hydrogen fuel cells provide an excellent power source for these aforementioned types of propulsion systems. However, as skilled persons will appreciate, a major concern of this promising power technology is the well known volatility of hydrogen. A small leak in the vicinity of a suitable ignition source can result in disaster.
Another approach to providing clean vehicular propulsion may be realized by employing pneumatic principles. Basic pneumatic powered vehicles include an air supply or an air reservoir tank having output lines that are coupled to power and energize pneumatic powered motors. Ideally, if a large enough supply of pressurized air is available, and an efficient motor and drive arrangement are provided, pneumatically powered vehicles may be quite desirable in a number of settings. For example, in cities and other locations having significant pollution problems.
However, previously known prior art pneumatic powered vehicles have been quite complicated in structure and operation. For example, see U.S. Pat. No. 4,370,857 to Miller and U.S. Pat. No. 4,596,119 to Johnson. Many of the disclosed pneumatic structures were large, consuming major portions of the available interior volume of the vehicle. Further, they have generally not been practical when considering their performance characteristics and limited operating range. As such, while useful on scaled down or conceptual vehicles, the presently known pneumatic vehicles were not adequate for general transporting of cargo and passengers for any substantial or practical distance. Improved efficiency of such vehicles and associated structures are needed.
Therefore, skilled individuals will understand a need for improved and efficient propulsion systems to power a large variety of vehicles to enable the transporting of cargo and individuals in an environmentally sound manner. In particular, there is a need for improved xe2x80x98cleanxe2x80x99 propulsion means and methods that are not based upon fossil-fuel burning constructions, and that don""t pollute. A full understanding of the present invention, including an understanding of a number of capabilities, characteristics, and associated novel features, will result from a careful review of the description and figures of several preferable embodiments provided herein. Attention is called to the fact, however, that the drawings and descriptions are illustrative only. Variations and alternate embodiments are contemplated as being part of the invention, limited only by the scope of the appended claims.
In accordance with the present invention, a vehicle is powered by a regenerative pneumatic propulsion system including a plurality of directly-driven radial compressor units. The propulsion system may preferably be installed within a vehicle configured with a chassis and a plurality of spaced wheels. At least one pneumatic powered motor is preferably supported upon an axle assembly of the vehicle, with the axle assembly structured having an elongated and hollow configuration. An interior chamber of the axle assembly establishes an interior volume for holding filtered air drawn in from end portions of the axle assembly. The interior chamber is formed in part by an outer wall structure of the axle assembly. The end portions of the outer wall structure are adapted to support filtered air intake ports enabling the filtered air to pass into the interior chamber.
The axle assembly of the present invention is further structured with a rotatable tubular drive member having portions thereof substantially disposed within the outer wall structure and operatively coupled to be driven and rotated by one or more of the pneumatic powered motors. The tubular drive member is suitably mounted and supported within the axle assembly utilizing friction reducing means such as roller bearings, etc. When energized with a flow of pressurized air, a pneumatic powered motor of the propulsion system will cause the rotating of the tubular drive member. Importantly, as at least one spaced drive wheel of the vehicle is coupled to be rotated with the rotatable tubular drive member of the axle assembly, such rotating will result in a propelling of the vehicle.
Another aspect of the present invention provides plurality of radial compressor units. Each of the compressor units, which are preferably substantially disk-like or cylindrical in shape, is preferably disposed in a juxtaposed arrangement, about and operatively coupled to the rotatable tubular drive member. In a most preferred configuration, each radial compressor unit will be positioned in a minimally spaced juxtaposed configuration, and will share a common center rotational axis. The common center rotational axis is occupied by a rotational center of the hollow axle assembly. Therefore, as one or more spaced wheels rotate with the tubular drive member, each xe2x80x98enabledxe2x80x99 compressor unit is structured for drawing filtered air from the interior volume of the axle assembly and producing pressurized air at an air outlet port of the compressor unit. The pressurized air produced by each compressor unit may most preferably be coupled to a pneumatic reservoir tank by way of an in-line pressure activated pneumatic check valve. Each check valve is arranged having an air inlet side and an air outlet side, and is structured for permitting a unidirectional flowing of air from the inlet side to the outlet side. Each air inlet side of a respective check valve is operatively coupled to accept air from an air outlet port of a compressor unit, while each air outlet side is coupled to deliver pressurized air to at least one pneumatic reservoir tank. As skilled individuals will understand, the use of the pneumatic check valve is useful for operational reasons, and will also add a degree of fault tolerance should one of a plurality of compressor units fail to operate properly.
The propulsion system of the invention also includes a means to enable an operator of the vehicle to couple a selected and adjustable flow of pressurized air from the reservoir tank to one or more pneumatic powered motors. This enables the operator to regulate the power produced by the pneumatic powered motors to power the vehicle in a controlled and desired manner. The means may most preferably be configured to couple pressurized air to a selected line(s) of a plurality of lines, each of which is coupled to a pneumatic powered motor. The particular lines selected and supplied with pressurized air may control a rotational rate, an applied rotational torque level, and or a direction of rotation, for rotating one or more drive wheels of the vehicle.